Effective Ship Domains Considering Ship Encounter Situations and Speeds

Abstract

Abstract Ship domain is an important concept in assessing navigation situation and planning collision avoidance manoeuvres of a ship. For purpose of improving the precision and adaptability of the ship domains, effective ship domains are proposed for ships with different speeds in a variety of encounter situations in this work. Firstly, the COLREGs-based division of encounter types and corresponding collision avoidance actions are further optimized. Therefore, the problem of unclear division of responsibilities caused by the intersection of relative position and relative heading is resolved. On this basis, ship domains are determined by the encounter situations and the target ship’s speed. More specifically, the ship domain is approximated to a circle, and the dependence of the domain size on the encounter situation and the target ship’s speed has been analysed and described, that enable us to determine effective ships domains for ships varying in speeds and encounter situations. The simulation results show that ships can make effective collision-avoidance actions in different encounter scenarios based on the optimized COLREGs-based division of encounter types and effective ship domains.